The Excavation And Support Process Of A Bedding Rock Slope And Its Stability Response

The stability of bedding rock slope has always been a difficult problem for engineering construction.Under the interference of human engineering activities,it is easy to be unstable,which will cause huge economic and property losses and even lead to human casualties.In the process of slope excavation,the causes of the slope stress redistribution,the effect of stress concentration,is now leading to a major factor of the slope unstability,however,inevitable in the process of slope engineering management to a certain slope excavation disturbance,so the slope stability in excavation support in the process of the response is very necessary.In mentougou qiupo village south slope bedding rock slope control engineering for research,first of all,on the basis of existing geological data collected before,then combined the field of geological survey,high density resistivity method and the engineering geological drilling method in geotechnical engineering,determine the bedding rock slope,structural plane of rock mass and geology,hydrological geology,the geological characteristics of many aspects,such as slope structure.Then,PLAXIS 3D software was used to establish a 3D geological model,and 9 major factors including the severity,cohesion and internal friction Angle of the carbonaceous shale,carbonaceous mudstone and carbonaceous sandstone that constitute the bedding rock slope were selected.The stability and sensitivity of the slope were analyzed based on the orthogonal test.Finally,PLAXIS 3D software is used for 3D numerical simulation calculation of the slope excavation and support process,and the stability coefficient,displacement,stress and strain changes and their characteristics of the slope during the excavation and support process are analyzed.Finally,the following conclusions are obtained:(1)This slope is a typical bedding rock slope with soft layer,and the soft layer iscarbonaceous mudstone with a thickness of 1~4m.There are two faults running through the whole slope.At present,the deformation and failure modes of the slope in the initial excavation and support process are mainly small area slide,crack and platform subsidence.(2)Nine selected factors on the stability of the bedding rock slope of the sensitivity can be divided into three categories,namely,high sensitivity,low sensitivity and sensitivity,the high sensitivity of the three factors are: carbonaceous mudstone of internal friction Angle,carbonaceous mudstone cohesive force,internal friction Angle of coal shale,the sensitivity of factors are: carbonaceous shale severely,carbonaceous shale,carbonaceous mudstone severe cohesive force,low sensitivity factors are: carbonaceous sandstone internal friction Angle,cohesive force,carbonaceous carbonaceous sandstone sandstone heavy.(3)Before phase 2,the stability coefficient of the slope has not significantly changed with the continuous development of the excavation support process,and has been in a stable state,and the stability coefficient of the slope has increased significantly after the completion of phase 3.The stability of the slope of the slope is the maximum,and the displacement of the slope is the maximum,but it is still in a stable state,and it proves the rationality and validity of the slope engineering management plan.The effect of the two layers of carbon shale control is fully met by the sensitivity analysis of the previous stability factors,and the main reason is that because of the rebound effect of the two layers of carbon clay in the slope of the slope of the slope,the deformation damage caused by the construction of the slope is mainly concentrated in the current construction area and the front of the slope.